22.00 X Factor judge Louis Walsh has been speaking on Irish radio station RTE Radio One about the "dark side" of One Direction and why it may have driven Malik to quit. He said:

I have heard the rumours for the last few weeks that everything wasn't happy in paradise.

The problem with these guys is they've been in a bubble for the last five years, pressure, working, a lot harder than people think, so something had to give. So Zayn was the first person just to crack up a little bit."

He's had an amazing time with the other guys. That's the good side of it. The dark side of it is all the travelling, the airports, in a bubble, not really seeing real life.

They burn out basically. The thing with One Direction is they were massive worldwide. They were going from continent to continent, right across America. Going from hotels to hotels, he probably didn't see light of day, he was just working, working, working.

Now it's everybody's dream, everybody loves it but there's an awful lot of pressure with it too.

21.55 Breaking news just in. Reports suggest that Harry Styles appeared to break down in tears on stage as he apparently struggled to come to terms with Zayn Malik's sudden departure from boyband One Direction.

Styles reportedly wiped away tears as the band performed the latest leg of their On The Road Again Tour in Jakarta, Indonesia, just hours after the news of Malik's leaving broke.

Harry Styles in happier days (PA)

21.10 Sue Minto, head of ChildLine, said it would be unhelpful for adults and other youngsters to "pooh pooh" the feelings of those struggling to cope with Malik leaving the band.

She said: "There are young people who are going to feel seriously distressed at the news, and people are going to have to get their head around the fact that for some this will be very distressing and not to undermine it, even if they don't quite understand it."

Ms Minto said there will be a "whole range of reasons" why the news will have an impact on young people - and not just on young girls who may have "fallen in love with him". She said:

It will be other young people for whom One Direction might be a positive thing in their life, something that maybe supports them and helps them out with other pressures such as bullying, exams or low self-esteem.

Lots of people have pop stars or celebrities or actors who they hold in high esteem, and there is a lot of sadness and impact for people when something happens to any of them.

So for a young person who maybe spends time in their room listening to One Direction and forgetting about their worries, to lose that could have a devastating effect.

20.10 Lidl have expressed their sincere sympathy for One Direction fans, and as a gesture of goodwill, they have announced a reduction in the price of their One Direction Easter eggs by 1/5, from 99p to 79p, from tomorrow morning. They even issued a statement about the "naturally devestating" news. How sweet.

A Lidl UK Spokesperson said:

This is naturally devastating news for all the 1D fans out there, ourselves included. In times like this only chocolate will do, so we've decided to reduce our One Direction Easter eggs by 1/5, to help make things a little easier for everyone.

Picture: Lidl

20.05 More celebrities have sent best wishes to Malik after his announcement.

Gary Barlow said: "Sending my best to all the 1D boys"

Sending my best to all the 1D boys ! #thatters we've all been there haven't we ? !!!!!

He first joined the British supergroup after narrowly avoiding elimination when he appeared on X Factor in 2010.

He was initially kicked off the show during the preliminary stages, before the judges decided to group him with four other solo artists - Harry Styles, Niall Horan, Liam Payne and Louis Tomlinson - to form One Direction.

Born Zain Malik, the young star is 1D's sole Yorkshireman, hailing from East Bowling, Bradford. He comes from a Muslim family and once tweeted an affirmation of his faith to his millions of followers.

He has been engaged to Little Mix singer Perrie Edwards since 2013 and has her face tattooed on his arm. He was previously linked with another member of the X Factor alumni, Rebecca Ferguson.

Malik is also One Direction's least popular member on social media - lagging four and a half million twitter followers behind Louis Tomlinson and almost 10 million behind Harry Styles.

He found himself the subject of considerable public criticism after a video appearing to show him and fellow band member Tomlinson smoking marijuana in Peru surfaced last year.

The pair both apologised and were this week ordered to lodge a £3,000 bond with the Peruvian government, which would be forfeited if they used or promoted the use of the drug during a scheduled show in Manila.

Malik again courted controversy a few months later by tweeting Free Palestine during the Israel-Gaza conflict in 2014, prompting outrage from some of the group's Israeli fans.

Band mates arriving for the World Premiere of One Direction: This Is Us, at the Empire Leicester Square, London (IAN WEST/PA)

One tweeted: "It broke me that one of my idols wants me to die."

Speculation about his future with the band has been mounting since last week when he walked away from their current world tour because he was suffering stress.

6:00pm Lets take a minute to remember the good times

17.45 Things are getting a little heated over on Twitter.

Within 45 minutes of the announcement, One Direction's official statement on Twitter had been re-tweeted 57,000 times and favourited 50,000 times. On Facebook the statement received more than 100,000 likes and 48,000 comments.

Despite Malik's departure, One Direction's fan base continued to swell on Twitter and Facebook, adding approximately a thousand new followers and fans every two minutes since the announcement.

The departure of Jeremy Clarkson from Top Gear just before Malik's exit led some to connect the two.

Comedian Dom Joly tweeted:

*BREAKING NEWS* Clarkson to replace Zayn Malik in One Direction "It'll take some training but we are determined to make it work"

17.28 Here are the statements in full from Malik, the band and Simon Cowell:

Zayn Malik:

My life with One Direction has been more than I could ever have imagined. But, after five years, I feel like it is now the right time for me to leave the band. I'd like to apologise to the fans if I've let anyone down, but I have to do what feels right in my heart.

I am leaving because I want to be a normal 22-year-old who is able to relax and have some private time out of the spotlight. I know I have four friends for life in Louis, Liam, Harry and Niall. I know they will continue to be the best band in the world.

One Direction:

We're really sad to see Zayn go, but we totally respect his decision and send him all our love for the future. The past five years have been beyond amazing, we've gone through so much together, so we will always be friends. The four of us will now continue. We're looking forward to recording the new album and seeing all the fans on the next stage of the world tour.

Simon Cowell:

I would like to say thank you to Zayn for everything he has done for One Direction. Since I first met Zayn in 2010, I have grown very, very fond - and immensely proud - of him.

I have seen him grow in confidence and I am truly sorry to see him leave. As for One Direction, fans can rest assured that Niall, Liam, Harry and Louis are hugely excited about the future of the band.

17.20 The news that there are now only four members of One Direction has hit the fans hard.

STOP TWEETING 'no 1D without zayn' I MEAN ITS TRUE BUT WOULD YOU LIKE THE BAND BREAK UP?

17.00 Malik quit the boyband's world tour last week after being "signed off with stress" and returned to the UK after he was forced to defend himself online and declare his love for fiancee Perrie Edwards when pictures emerged of him apparently close to another woman.

In a statement, the rest of the group said:

We're really sad to see Zayn go, but we totally respect his decision and send him all our love for the future.

The past five years have been beyond amazing - we've gone through so much together, so we will always be friends.

The four of us will now continue. We're looking forward to recording the new album and seeing all the fans on the next stage of the world tour.

Simon Cowell, who discovered the boyband on talent show The X Factor, said:

I would like to say thank you to Zayn for everything he has done for One Direction.

Since I first met Zayn in 2010, I have grown very, very fond - and immensely proud - of him. I have seen him grow in confidence and I am truly sorry to see him leave.

"As for One Direction, fans can rest assured that Niall, Liam, Harry and Louis are hugely excited about the future of the band."

After five incredible years Zayn Malik has decided to leave OneDirection. Niall, Harry, Liam and Louis will continue as...